Access to the blood stream via a needle is perhaps the most common procedure administered by healthcare professionals, and may be referred to as Blood Vessel Medical Treatment (hereinafter referred to as ‘BVMT’). Access to the blood stream is required both for the administration of drugs, for example intravenous drug administration via a drip, and/or for monitoring purposes, via blood testing for example for tracking an analyst such as glucose levels, cholesterol, cardiac enzymes and the like. Therefore access to the blood stream is requirement for most medical testing and monitoring procedures. However to date, despite technological advancements identification and gaining access to the blood stream remains a difficult procedure for some groups, particularly for the young, old, premature babies and obese individuals. This is due to the fact that visualization of the blood vessel is not readily available to the naked eye while practitioners rely on experience and skill to quickly and properly identify the blood vessel so as to gain access to it.
The lack of visibility in these groups may be due to various reasons: location (depth of vessel), size (small thickness). Difficulty in locating the vessels makes the needle intrusion procedure very difficult and at times risky, resulting in many false attempts leading to multiple and needless needle penetrations.
Technology currently available to facilitate blood vessel identification have been introduced to attempt to identify the location of a blood vessel by non-invasive visual means using heat, ultrasound, and light sources. However these systems are limited in a variety of ways, for example they are cumbersome, expensive to manufacture, difficult to use, and at times do not accurately identify the blood vessel location.
Currently there are number of available products for locating BVs. This include products utilizing (1) Ultrasonic imaging, such as the Bard Site-Ride 5 Ultrasound system marketed by Bard Access Systems, INC. of Salt Lake City, Utah, (2) NIR Imaging, such as the IRIS Vascular Viewer marketed by Infrared Imaging Systems, INC and the Vein-Viewer Imaging systems marketed by Cristis (Luminetx), (3) Liquid Crystal thermal surface temperature measurement patches, such as the K-4000 Vena-Vue Thermographic Vein Evaluator manufactured by Biosynergy, Inc. of Elk Grove Village, III., (4) visible light illumination, such as the Venoscope II Transilluminator/Vein Finder and the Neonatal Transilluminator marketed by Venoscope, L.L.C. of Lafayette, La., and the VeinLite LED, Veilite EMS and Veinlite PEDI manufactured by TransLite LLC of Sugar Land, Tex.
The infrared (‘IR’) and/or near infrared (‘NIR’) imaging techniques relies on the fact that blood vessels have low light reflection in the IR wavelength spectrum. At this wavelength range, the difference in reflection between blood vessel and skin is very high. Thus an IR imaging system can obtain much better indication of the blood vessel location particularly when compared to the naked eye.
Systems utilizing IR/NIR for blood vessel location are known by the name of Vein-Viewers that project the capture image back on the body surface, thus enabling the operator to easily locate the blood vessel. Such systems are commercially available and they become more and more distributed in the world. It was proven that those tools dramatically improve the rate success of blood vessel intrusion. It is the intention of the presented method to simplifying those methods while reducing the cost and improving efficiency while keeping the system performance. An example of such a system is described in U.S. Pat. Nos. 5,969,754 and 6,556,858 incorporated herein by reference as well as a publication entitled “The Clinical Evaluation of Vein Contrast Enhancement”.
Luminetx is currently marketing such a device under the name “Veinviewer Imaging System” and information related thereto is available on its website, which is incorporated herein by reference.
The Luminetx Vein Contrast Enhancer (hereinafter referred to as ‘LVCE’) utilizes an infrared light source for flooding the region to be enhanced with infrared light generated by an array of LEDs. A CCD imager is then used to capture an image of the infrared light reflected off the patient. The resulting captured image is then projected by a visible light projector onto the patient in a position closely aligned with the image capture system. Given that the CCD imager and the image projector are both two dimensional, and do not occupy the same point in space, it is relatively difficult to design and build a system that closely aligns the captured image and the projected image.
A further characteristic of the LVCE is that both the imaging CCD and the projector have fixed focal lengths. Accordingly, the patient must be at a relatively fixed distance relative to the LVCE. This necessitates that the LVCE be positioned at a fixed distance from the region of the patient to be enhanced.
The LVCE system, for example by luminetx is limited in that it required that the system be mobile to reach individual patients and therefore limited in its use in that they system has to be used in real time to provide its effect however its use remains in a one to one ratio where each system requires a system, practitioner and patient in real time in order to utilize the system.
Other systems have attempted to overcome this problem by introducing a miniature mobile vein enhancer, described in U.S. Pat. No. 7,904,138 to Goldman et al, where the enhancer may be worn by a patient during the procedure. However this does not overcome the problem of needing a one to one to one ratio, where patient, device and practitioner have to be on site in real time to realize the device's potential as it projects an enhanced image of the scanned area onto the target site.
Other systems such as that described by U.S. Pat. No. 6,464,646 to Shalom et al, teach a temperature sensitive device capable of locating and marking a hot spot about a treatment area of scanned skin. However such a system is limited in that a temperature based system is dependent on temperature changes, which is highly variable and cannot produce sufficiently repetitive and accurate depiction of the location of a blood vessel. Accordingly although a hot spot may be identified and potentially marked, the hot spot location cannot guarantee the location of a blood vessel over time, due to temperature fluctuations over time.